I think that is rather unfair to Bing. They are after all in competition with Google and have made a number of improvements to their webmaster tools, this being one of them.
It is true to say that they haven't sent out unnatural links warnings or launched the equivalent of Penguin, so that people were not asking them for such a tool. But they have taken the opportunity to get in front of Google for once by providing it, and I don't think that will have done them any harm.

Not unfair to Bing its just the truth. They had no reason for disavowing links only for a brownie point in beating Google to it. Props to them for doing however it has no effect on their search results.

I am all for competition anyway we can't let Google run a monopoly. Cake is for sharing!